US carriers now block application-to-person business texts sent from unregistered numbers. The worst part: the failure is silent. Your software reports the message as sent, but it never reaches the phone. The fix is registering your Brand and your Campaign so carriers recognize your traffic as legitimate.
If your text reply rate dropped to almost nothing, this is probably why. A message that never arrives does not bounce back with an error. It reports as delivered inside your dashboard, so everything looks fine while your customers hear silence. That gap is exactly what lets this problem run unnoticed for months.
What A2P 10DLC actually means
A2P stands for application-to-person. It covers any text sent by software instead of typed by hand, so automated reminders, missed-call responses, and review requests all count. 10DLC means a standard 10-digit long code, which is the normal local phone number your business already uses.
Put those together and A2P 10DLC is the framework US carriers use to tell legitimate business texting apart from spam. The registration record lives in a system called The Campaign Registry (TCR). Carriers check your traffic against it before they hand a message to the phone.
What changed, and roughly when
This is not a rule you forgot to follow. Enforcement tightened in stages between 2023 and 2025. Carriers began adding surcharges to unregistered traffic, then the major US carriers moved from filtering it to blocking it outright.
Now unregistered A2P messages are blocked at the network level, not just filtered into a spam folder. So a number that texted fine two years ago can be fully blocked today with nothing on your end changing. The rules moved. Your setup did not.
Brand registration vs Campaign registration
Two separate things have to be registered, and skipping either one leaves you blocked.
- Brand registration identifies your business. It ties your legal name, EIN, and contact details to your traffic, and the carriers vet that record.
- Campaign registration describes what you actually send. Appointment reminders, review requests, and promotions are different use cases, each needing sample messages and opt-in wording.
Your Brand is approved once. Each Campaign is reviewed on its own, and the sample texts you submit have to match what you really send. Vague or mismatched samples are a common reason a campaign gets rejected.
Why nobody told you it broke
The failure is silent by design. Carriers block the message at the network level, so the sending platform often still logs it as sent. No error lands in your inbox. You find out the slow way, when a lead who asked for a callback never texts back, or a review request goes out to fifty customers and returns zero replies.
By the time the pattern is obvious, you have usually lost weeks of follow-up. Here is how the two states compare.
| Factor | Registered A2P | Unregistered |
|---|---|---|
| Does the text arrive | Yes, to the handset | Often no, blocked at the carrier |
| Deliverability | High and consistent | Drops off, then stops entirely |
| Throughput limits | Set by your vetted trust score | Throttled hard or reduced to zero |
| Carrier fees | Standard per-message rate | Extra surcharge added to unregistered traffic |
| Risk of number being blocked | Low while you stay compliant | High, the number can be blacklisted |
Why this matters for every lead you chase
Most home service automation runs on text. Missed-call text-back fires the moment you cannot pick up, and it only helps if that text actually lands. The same is true for review requests, appointment confirmations, and quote follow-ups. When the messages are blocked, your automation is running straight into a wall you cannot see.
For a junk removal or home service business where speed to the lead decides who books the job, a silently blocked text is a booked job handed to a competitor. The tool is not broken. The number was simply never allowed to reach the customer.
What to actually do about it
- Confirm whether your numbers are registered in TCR through your texting platform or provider.
- Register your Brand first, with details that match your IRS and EIN records exactly, since mismatches cause rejections.
- Register each Campaign with honest sample messages and clear opt-in language.
- Fix the opt-in wording on your web forms, because carriers check how you collect consent.
- Once approved, send test texts to real phones on AT&T, T-Mobile, and Verizon before you trust the automation again.
Registration usually takes 1 to 3 weeks end to end. Brand approval can land in a day or two, while each campaign review commonly runs 3 to 7 business days when the submission is clean. This is fiddly, technical work, and it is the kind of thing we handle as part of setting up messaging that holds up.
Questions
How do I know if my texts are affected?
Send a test to phones on AT&T, T-Mobile, and Verizon, then confirm they truly arrive, not just that your dashboard says sent. A sudden drop in replies, opt-outs, or booked jobs from text is another strong signal. If you have never registered in TCR, assume you are affected.
How long does registration take?
Plan for 1 to 3 weeks overall. Brand approval is often quick, sometimes a day or two. Each campaign is reviewed separately and usually takes 3 to 7 business days when the information is accurate and the sample messages match your real texts.
Do I need this if I only text a few customers?
Yes. The rule is about automated business texting to US numbers, not about volume. Even a handful of software-sent reminders from an unregistered number can be blocked. Low volume does not exempt you.
Does this apply outside the US?
A2P 10DLC is a US carrier requirement, and it applies to any business texting US phone numbers, wherever your company is based. Canada runs its own separate rules, and messaging into the UK from US or Canadian numbers is a different setup again. If you text US customers, you register.